Genetic Diversity of the Four Shell Color Families of Pinctada martensii by SSR Marker System

According to different shell color phenotypes of Pinctada martensii, the shell color was purified by group of hybridization and continuous progeny selection and distinct Pinctada martensi selection strains with four shell colors(white, black, yellow, and red) were acquired, then the microsatellite DNA technique was applied to estimate genetic structure of four shell color families of Pinctada martensii. By using six microsatellite loci, genetic parameters were calculated as followed:the average effective numbers of alleles of the four families were from 1.297 to 1.819. The average expected heterozygosity and the average observed heterozygosity were 0.207 ~ 0.341 and 0.083 ~ 0.212, respectively. PIC values were between 0.257 ~ 0.442. Shannon's diversity was 0.366-0.616.The indices of Hardy-Weinberg were highly significant deviation in four color families. FST values between four families were from 0.113~0.793. Genetic distance become larger, four families have lower genetic diversity. The results serve as reference for the purification of shell color and genetic breeding. Comparing ordinary breeding groups with shell selection strains F5, Genetic distance between four shell color families became larger and genetic diversity was lower. The results provide reference for the purification of shell color and genetic breeding.